Systems and methods for providing singulation of objects for processing

ABSTRACT

A processing system including a singulation system is disclosed. The singulation system includes a conveying system for moving objects to be sorted from a source area along a first direction, a detection system for detecting objects at the conveying system, and for selecting certain selected objects for removal from the conveying system, and a removal system for removing the certain selected objects from the conveying system for providing a singulated stream of objects.

PRIORITY

The present application is a divisional of U.S. patent application Ser.No. 15/824,009, filed Nov. 28, 2017, which claims priority to U.S.Provisional Patent Application Ser. No. 62/426,913, filed Nov. 28, 2016,the contents of which are hereby incorporated by reference in theirentireties.

BACKGROUND

The invention generally relates to automated, robotic and othersortation and other processing systems, and relates in particular toautomated and robotic systems intended for use in environmentsrequiring, for example, that a variety of objects (e.g., articles,parcels or packages) be sorted and/or distributed to several outputdestinations.

Many object distribution systems receive objects in a disorganizedstream that may be provided as individual objects or objects aggregatedin groups such as in bags, arriving on any of several differentconveyances, commonly a conveyor, a truck, a pallet, a Gaylord, or abin. Each object must then be distributed to the correct destinationcontainer, as determined by identification information associated withthe object, which is commonly determined by a label printed on theobject or on a sticker on the object. The destination container may takemany forms, such as a bag or a bin.

The sortation of such objects has traditionally been done, at least inpart, by human workers that scan the objects, e.g., with a hand-heldbarcode scanner, and then place the objects at assigned locations. Forexample many order fulfillment operations achieve high efficiency byemploying a process called wave picking. In wave picking, orders arepicked from warehouse shelves and placed at locations (e.g., into bins)containing multiple orders that are sorted downstream. At the sortingstage individual objects are identified, and multi-object orders areconsolidated, for example into a single bin or shelf location, so thatthey may be packed and then shipped to customers. The process of sortingthese objects has traditionally been done by hand. A human sorter picksan object from an incoming bin, finds a barcode on the object, scans thebarcode with a handheld barcode scanner, determines from the scannedbarcode the appropriate bin or shelf location for the article, and thenplaces the article in the so-determined bin or shelf location where allobjects for that order have been defined to belong. Automated systemsfor order fulfillment have also been proposed. See for example, U.S.Patent Application Publication No. 2014/0244026, which discloses the useof a robotic arm together with an arcuate structure that is movable towithin reach of the robotic arm.

Other ways of identifying objects by code scanning either require manualprocessing, or require that the code location be controlled orconstrained so that a fixed or robot-held code scanner (e.g., barcodescanner) can reliably detect it. Manually operated barcode scanners aregenerally either fixed or handheld systems. With fixed systems, such asthose used at point-of-sale systems, the operator holds the object andplaces it in front of the scanner so that the barcode faces the scanningdevice's sensors, and the scanner, which scans continuously, decodes anybarcodes that it can detect. If the object is not immediately detected,the person holding the object typically needs to vary the position orrotation of the object in front of the fixed scanner, so as to make thebarcode more visible to the scanner. For handheld systems, the personoperating the scanner looks for the barcode on the object, and thenholds the scanner so that the object's barcode is visible to thescanner, and then presses a button on the handheld scanner to initiate ascan of the barcode.

Further, many current distribution center sorting systems generallyassume an inflexible sequence of operations whereby a disorganizedstream of input objects is first singulated into a single stream ofisolated objects presented one at a time to a scanner that identifiesthe object. An induction element or elements (e.g., a conveyor, a tilttray, or manually movable bins) transport the objects to the desireddestination or further processing station, which may be a bin, a chute,a bag or a conveyor etc.

In conventional parcel sortation systems, human workers or automatedsystems typically retrieve objects in an arrival order, and sort eachobject into a collection bin based on a set of given heuristics. Forinstance, all objects of like type might go to a collection bin, or allobjects in a single customer order, or all objects destined for the sameshipping destination, etc. The human workers or automated systems arerequired to receive objects and to move each to their assignedcollection bin. If the number of different types of input (received)objects is large, a large number of collection bins is required.

Such a system has inherent inefficiencies as well as inflexibilitiessince the desired goal is to match incoming objects to assignedcollection bins. Such systems may require a large number of collectionbins (and therefore a large amount of physical space, large capitalcosts, and large operating costs) in part, because sorting all objectsto all destinations at once is not always most efficient.

Current state-of-the-art sortation systems rely on human labor to someextent. Most solutions rely on a worker that is performing sortation, byscanning an object from an induction area (chute, table, etc.) andplacing the object in a staging location, conveyor, or collection bin.When a bin is full or the controlling software system decides that itneeds to be emptied, another worker empties the bin into a bag, box, orother container, and sends that container on to the next processingstep. Such a system has limits on throughput (i.e., how fast can humanworkers sort to or empty bins in this fashion) and on number of diverts(i.e., for a given bin size, only so many bins may be arranged to bewithin efficient reach of human workers).

Other partially automated sortation systems involve the use ofrecirculating conveyors and tilt trays, where the tilt trays receiveobjects by human sortation, and each tilt tray moves past a scanner.Each object is then scanned and moved to a pre-defined location assignedto the object. The tray then tilts to drop the object into the location.Other systems that include tilt trays may involve scanning an object(e.g., using a tunnel scanner), dropping the object into a tilt tray,associating the object with the specific tilt tray using a knownlocation or position, for example, using beam breaks, and then causingthe tilt tray to drop the object when it is at the desired location.

Further, partially automated systems, such as the bomb-bay stylerecirculating conveyor, involve having trays open doors on the bottom ofeach tray at the time that the tray is positioned over a predefinedchute, and the object is then dropped from the tray into the chute.Again, the objects are scanned while in the tray, which assumes that anyidentifying code is visible to the scanner.

Such partially automated systems are lacking in key areas. As noted,these conveyors have discrete trays that can be loaded with an object;the trays then pass through scan tunnels that scan the object andassociate it with the tray in which it is riding. When the tray passesthe correct bin, a trigger mechanism causes the tray to dump the objectinto the bin. A drawback with such systems however, is that every divertrequires an actuator, which increases the mechanical complexity and thecost per divert can be very high.

An alternative is to use human labor to increase the number of diverts,or collection bins, available in the system. This decreases systeminstallation costs, but increases the operating costs. Multiple cellsmay then work in parallel, effectively multiplying throughput linearlywhile keeping the number of expensive automated diverts at a minimum.Such diverts do not ID an object and cannot divert it to a particularspot, but rather they work with beam breaks or other sensors to seek toensure that indiscriminate bunches of objects get appropriatelydiverted. The lower cost of such diverts coupled with the low number ofdiverts keep the overall system divert cost low.

Unfortunately, these systems don't address the limitations to totalnumber of system bins. The system is simply diverting an equal share ofthe total objects to each parallel manual cell. Thus each parallelsortation cell must have all the same collection bins designations;otherwise an object might be delivered to a cell that does not have abin to which that object is mapped. There remains a need for a moreefficient and more cost effective object sortation system that sortsobjects of a variety of sizes and weights into appropriate collectionbins or trays of fixed sizes, yet is efficient in handling objects ofsuch varying sizes and weights.

SUMMARY

In accordance with an embodiment, the invention provides a processingsystem including a singulation system. The singulation system includes aconveying system for moving objects to be sorted from a source areaalong a first direction, a detection system for detecting objects at theconveying system, and for selecting certain selected objects for removalfrom the conveying system, and a removal system for removing the certainselected objects from the conveying system for providing a singulatedstream of objects.

In accordance with another embodiment, the invention provides asingulation system that includes a conveying system for moving objectsto be sorted from a source area along a first direction, a detectionsystem for selecting certain selected objects for removal from theconveying system, and a removal system for removing the certain selectedobjects from the conveying system and for returning the certain selectedobjects to the source area such that a singulated stream of objects maybe provided to an object processing system.

In accordance with a further embodiment, the invention provides a methodof providing singulation of objects. The method includes the steps ofmoving objects to be sorted from a source area along a first directionat a conveying station, detecting objects at the conveying system,selecting certain selected objects for removal from the conveyingsystem, and removing the certain selected objects from the conveyingsystem.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description may be further understood with reference tothe accompanying drawings in which:

FIG. 1 shows an illustrative diagrammatic view of a system in accordancewith an embodiment of the present invention;

FIG. 2 shows an illustrative diagrammatic view of the system of FIG. 1wherein an object is being returned to an input bin for purposes ofproviding a singulated stream of objects;

FIG. 3 shows an illustrative diagrammatic view of a system in accordancewith another embodiment of the present invention;

FIG. 4 shows an illustrative diagrammatic view of a system in accordancewith a further embodiment of the present invention that includes a pushdevice;

FIG. 5 shows an illustrative diagrammatic view of a system in accordancewith a further embodiment of the present invention that includes a pulldevice;

FIG. 6 shows an illustrative diagrammatic front view of a drop scannerin accordance with an embodiment of the present invention;

FIG. 7 shows an illustrative diagrammatic rear view of the drop scannershown in FIG. 5;

FIG. 8 shows an illustrative diagrammatic view of an object processingsystem in accordance with an embodiment of the present invention;

FIG. 9 shows an illustrative diagrammatic view of an object processingsystem in accordance with another embodiment of the present invention;

FIG. 10 shows an illustrative diagrammatic view of a shuttle section inthe system shown in FIGS. 8 and 9;

FIG. 11 shows an illustrative diagrammatic view of the carriage on thetrack adjacent bins in the shuttle section shown in FIG. 10;

FIG. 12 shows an illustrative diagrammatic view of the carriage of FIG.11 dropping its contents into a bin in the shuttle section of FIG. 10;

FIG. 13 shows an illustrative top view of a bin in the shuttle sectionshown in FIG. 10;

FIG. 14 shows an illustrative diagrammatic view of a system inaccordance with a further embodiment of the present invention thatincludes carriages that receive objects from a drop scanner;

FIG. 15 shows an illustrative diagrammatic view of the carriage on thetrack adjacent bins in the shuttle section shown in FIG. 14;

FIG. 16 shows an illustrative diagrammatic view of the carriage of FIG.15 dropping its contents into a bin in the shuttle section of FIG. 14;

FIG. 17 shows an illustrative diagrammatic view of the system of FIG. 14while a bin is being replaced;

FIG. 18 shows an illustrative diagrammatic view of a flowchart showingselected processing steps in a system in accordance with an embodimentof the present invention; and

FIG. 19 shows an illustrative diagrammatic view of a flowchart showingbin assignment and management steps in a system in accordance with anembodiment of the present invention;

The drawings are shown for illustrative purposes only.

DETAILED DESCRIPTION

In accordance with an embodiment, the invention provides a processing(e.g., sortation) system that includes an input system for receiving awide variety of objects to be sorted, and a singulation system forproviding a singulated stream of objects for efficient processing of theobjects. In further embodiments, the system may include anidentification system for identifying objects, and an output system forproviding the singulated stream of objects at desired outputdestinations. Individual parcels need to be identified and conveyed todesired parcel-specific locations. The described systems reliablyautomate the identification and conveyance of such parcels, employing incertain embodiments, a set of conveyors and sensors and a robot arm. Inshort, applicants have discovered that when automating the sortation ofobjects, there are a few main things to consider: 1) the overall systemthroughput (parcels sorted per hour), 2) the number of diverts (i.e.,number of discrete locations to which an object can be routed), 3) thetotal area of the sortation system (square feet), 4) sort accuracy, and5) the annual costs to run the system (man-hours, electrical costs, costof disposable components).

Sorting objects in a distribution center is one application forautomatically identifying and sorting parcels. In a shippingdistribution center, parcels commonly arrive in trucks, totes, Gaylordsor other vessels for delivery, are conveyed to sortation stations wherethey are sorted according to desired destinations, aggregated in bags,and then loaded in trucks for transport to the desired destinations.Another application would be in the shipping department of a retailstore or order fulfillment center, which may require that parcels besorted for transport to different shippers, or to different distributioncenters of a particular shipper. In a shipping or distribution centerthe parcels may take the form of plastic bags, boxes, tubes, envelopes,or any other suitable container, and in some cases may also includeobjects not in a container. In a shipping or distribution center thedesired destination is commonly obtained by reading identifyinginformation printed on the parcel or on an attached label. In thisscenario the destination corresponding to identifying information iscommonly obtained by querying the customer's information system. Inother scenarios the destination may be written directly on the parcel,or may be known through other means.

In accordance with various embodiments, therefore, the inventionprovides a method of taking individual parcels from a disorganizedstream of parcels, providing a singulated stream of objects, identifyingindividual parcels, and sorting them to desired destinations. Theinvention further provides methods for loading parcels into the system,for conveying parcels from one point to the next, for excludinginappropriate or unidentifiable parcels, for grasping parcels, fordetermining grasp locations, for determining robot motion trajectories,for transferring parcels from one conveyor to another, for aggregatingparcels and transferring to output conveyors, for digital communicationwithin the system and with outside information systems, forcommunication with human operators and maintenance staff, and formaintaining a safe environment.

Important components of an automated parcel identification and sortationsystem, in accordance with an embodiment of the present invention, areshown in FIG. 1. FIG. 1 shows a system 10 that includes an infeed hopper12 into which objects 14 may be dumped, e.g., by a dumper or Gaylord. Aninfeed conveyor 16 conveys objects from the infeed hopper 12 to primaryconveyor 20. The infeed conveyor 16 may include baffles 18 or cleats forassisting in lifting the objects 14 from the hopper 12 onto a primaryconveyor 20. Primary perception system 22 surveys the objects 14 toidentify objects when possible and to determine good grasp points. Robotarm 24 with gripper 26 grips objects 14, and as shown in FIG. 2, movesselected objects 14 to a return chute 28 for return to the input hopper12.

As shown in FIG. 1, a system 10 may provide that a portion of the inputstream is selectively adjusted by the robotic arm 24 to provide asingulated stream 30 of objects (as may be detected and confirmed by aperception unit 32). In particular objects are identified by the primaryperception unit 22 as being selected for removal, and the robotic arm 24is engaged to selectively remove objects from the input stream to createa singulated stream of objects. As shown in FIG. 2, the removed objects14 are placed by the gripper 26 of the robotic arm onto a return chute28 that returns the selected objects to the input bin 12. Significantly,a singulated stream of objects is provided (as shown at 30), and thissingulated stream of objects may be delivered to a drop perception unit34 (as discussed below) as a singulated stream and without requiringthat a robotic system place objects into the drop perception unit. Byproviding a singulated stream of objects for processing, the system isable to more effectively control the object processing rate, reducingthe incidence of errors that may occur, for example of two objects inclose contact with each other are perceived as being one object. Theinfeed conveyor 16 may also be in communication with the controller 78and the robotic arm 24, and speed of the infeed conveyor 16 may beadjusted to either slow down if moving too fast, or speed up if systemdetermines that more bandwidth exists for a faster input. The speed anddirection of the conveyor 20 may also be adjusted as may be necessary.

As further shown in FIG. 3, the conveyor 20 may further be provided withcleats 38 such that when the singulated stream of objects 30 isprovided, it is provided such that one object is positioned within onecleated area. The remaining elements of the system of FIG. 3 are thesame as those of FIGS. 1 and 2 and bear the same reference numerals. Asshown in FIG. 4, in accordance with further embodiments, the singulationsystem may employ a diverter 40 that includes a push bar 42 that may beemployed to push an object that is intended for removal into a returnchute 44 for return to the input hopper 12. Again, a singulated streamof objects 30 is provided. As shown in FIG. 5, in accordance withfurther embodiments, the singulation system may employ a diverter 50that includes a pull bar 48 that may be employed to pull an object thatis intended for removal into a return chute 44 for return to the inputhopper 12. Again, a singulated stream of objects 30 is provided.

The secondary perception system 34 may be supported by stands or may besuspended from above. As further shown in FIGS. 6 and 7, the secondaryperception system 34 may include a structure 52 having a top opening 54and a bottom opening 56, and may be covered by an enclosing material 58(a portion of which is shown in FIG. 6), e.g., a colored covering suchas orange plastic, to protect humans from potentially dangerously brightlights within the secondary perception system. The structure 52 includesa plurality of rows of sources (e.g., illumination sources such as LEDs)60 as well as a plurality of perception units (e.g., cameras) 62. Thesources 60 are provided in rows, and each is directed toward the centerof the opening. The perception units 62 are also generally directedtoward the opening, although some cameras are directed horizontally,while others are directed upward, and some are directed downward. Thesystem 34 also includes an entry source (e.g., infrared source) 64 aswell as an entry detector (e.g., infrared detector) 66 for detectingwhen an object has entered the perception system 34. The LEDs andcameras therefore encircle the inside of the structure 52, and thecameras are positioned to view the interior via windows that may includea glass or plastic covering (e.g., 68). The entire structure 52 may becovered by an enclosing material such as a colored covering such asorange plastic, to protect humans from potentially dangerously brightlights within the secondary perception system.

An important aspect of systems of certain embodiments of the presentinvention, is the ability to identify via barcode or other visualmarkings (e.g., as shown at 15 in FIG. 12) objects by employing aperception system into which objects may be dropped. Automated scanningsystems would be unable to see barcodes on objects that are presented ina way that their barcodes are not exposed or visible. The perceptionsystem may be used in certain embodiments, with a robotic system thatmay include a robotic arm equipped with sensors and computing, that whencombined is assumed herein to exhibit the following capabilities: (a) itis able to pick objects up from a specified class of objects, andseparate them from a stream of heterogeneous objects, whether they arejumbled in a bin, or are singulated on a motorized or gravity conveyorsystem; (b) it is able to move the object to arbitrary places within itsworkspace; (c) it is able to place objects in an outgoing bin or shelflocation in its workspace; and, (d) it is able to generate a map ofobjects that it is able to pick, represented as a candidate set of grasppoints in the workcell, and as a list of polytopes enclosing the objectin space.

The allowable objects are determined by the capabilities of the roboticsystem. Their size, weight and geometry are assumed to be such that therobotic system is able to pick, move and place them. These may be anykind of ordered goods, packages, parcels, or other articles that benefitfrom automated sorting. Each object is associated with uniqueidentifying indicia (identity or destination, such as a bar code or aunique address), which identifies the object or its destinationlocation.

The manner in which inbound objects arrive may be for example, in one oftwo configurations: (a) inbound objects arrive piled in bins ofheterogeneous objects; or (b) inbound articles arrive by a movingconveyor. The collection of objects includes some that have exposed barcodes and other objects that do not have exposed bar codes. The roboticsystem is assumed to be able to pick items from the bin or conveyor. Thestream of inbound objects is the sequence of objects as they areunloaded either from the bin or the conveyor.

The manner in which outbound objects are organized is such that objectsare placed in a bin, shelf location or cubby, into which all objectscorresponding to a given order are consolidated. These outbounddestinations may be arranged in vertical arrays, horizontal arrays,grids, or some other regular or irregular manner, but which arrangementis known to the system. The robotic pick and place system is assumed tobe able to place objects into all of the outbound destinations, and thecorrect outbound destination is determined from the unique identifyingindicia (identity or destination) of the object.

It is assumed that the objects are marked in one or more places on theirexterior with a visually distinctive mark such as a barcode orradio-frequency identification (RFID) tag so that they may be identifiedwith a scanner. The type of marking depends on the type of scanningsystem used, but may include 1D or 2D barcode symbologies. Multiplesymbologies or labeling approaches may be employed. The types ofscanners employed are assumed to be compatible with the markingapproach. The marking, either by barcode, RFID tag, or other means,encodes a symbol string, which is typically a string of letters andnumbers. The symbol string uniquely associates the object with uniqueidentifying indicia (identity or destination).

The operations of the systems described herein are coordinated by thecentral control system 78 as shown in FIGS. 1-5, 8, 9, 14 and 17. Thissystem determines from symbol strings the UPC associated with an object,as well as the outbound destination for the object. The central controlsystem is comprised of one or more workstations or central processingunits (CPUs). The correspondence between UPCs and outbound destinationsis maintained by the central control system in a database called amanifest. The central control system maintains the manifest bycommunicating with a warehouse management system (WMS).

During operation, the broad flow of work may be generally as follows.First, the system is equipped with a manifest that provides the outbounddestination for each inbound object. Next, the system waits for inboundobjects to arrive either in a bin or on a conveyor. The robotic systemmay drop one item at a time from the primary conveyor, and may drop eachitem into the perception system discussed above. If the perceptionsystem successfully recognizes a marking on the object, then the objectis then identified and forwarded to a sorting station or otherprocessing station. If the object is not identified, the robotic systemmay either replace the object back onto the input conveyor and tryagain, or the conveyor may divert the object to a human sortation bin tobe reviewed by a human.

The sequence of locations and orientations of the perception units 62are chosen so as to minimize the average or maximum amount of time thatscanning takes. Again, if the object cannot be identified, the objectmay be transferred to a special outbound destination for unidentifiedobjects, or it may be returned to the inbound stream. This entireprocedure operates in a loop until all of the objects in the inbound setare depleted. The objects in the inbound stream are automaticallyidentified, sorted, and routed to outbound destinations.

In accordance with an embodiment therefore, the invention provides asystem for sorting objects that arrive in inbound bins and that need tobe placed into a shelf of outbound bins, where sorting is to be based ona unique identifier symbol. Key specializations in this embodiment arethe specific design of the perception system so as to maximize theprobability of a successful scan, while simultaneously minimizing theaverage scan time. The probability of a successful scan and the averagescan time make up key performance characteristics. These key performancecharacteristics are determined by the configuration and properties ofthe perception system, as well as the object set and how they aremarked.

The two key performance characteristics may be optimized for a givenitem set and method of barcode labeling. Parameters of the optimizationfor a barcode system include the number of barcode scanners, where andin what orientation to place them, and what sensor resolutions andfields of view for the scanners to use. Optimization can be done throughtrial and error, or by simulation with models of the object.

Optimization through simulation employs a barcode scanner performancemodel. A barcode scanner performance model includes the range ofpositions, orientations and barcode element size from which a barcodesymbol can be detected and decoded by the barcode scanner, where thebarcode element size is the size of the smallest feature on the barcode.These are typically rated at a minimum and maximum range, a maximum skewangle, a maximum pitch angle, and a minimum and maximum tilt angle.

Typical performance for camera-based barcode scanners are that they areable to detect barcode symbols within some range of distances as long asboth pitch and skew of the plane of the symbol are within the range ofplus or minus 45 degrees, while the tilt of the symbol can be arbitrary(between 0 and 360 degrees). The barcode scanner performance modelpredicts whether a given barcode symbol in a given position andorientation will be detected.

The barcode scanner performance model is coupled with a model of wherebarcodes would expect to be positioned and oriented. A barcode symbolpose model is the range of all positions and orientations, in otherwords poses, in which a barcode symbol will expect to be found. For thescanner, the barcode symbol pose model is itself a combination of anarticle gripping model, which predicts how objects will be held by therobotic system, as well as a barcode-item appearance model, whichdescribes the possible placements of the barcode symbol on the object.For the scanner, the barcode symbol pose model is itself a combinationof the barcode-item appearance model, as well as an inbound-object posemodel, which models the distribution of poses over which inboundarticles are presented to the scanner. These models may be constructedempirically, modeled using an analytical model, or approximate modelsmay be employed using simple sphere models for objects and a uniformdistributions over the sphere as a barcode-item appearance model.

With reference to FIG. 8, in a processing system 100 of an embodiment ofthe invention, objects 14 passing through the secondary perception unit34 fall onto secondary conveyor 36. Diverters 70 including push bars 72divert objects to shuttle sections 74 as appropriate. While only twosuch diverters and shuttle sections are shown, any number of suchdiverters and shuttle sections may be used. Unidentified objects orotherwise unacceptable objects continue along secondary conveyor 36 andfall into secondary exception bin 76. The diverters 70 are incommunication with the controller 78, which is in communication with thescanner 32 as well as the indexing position of the conveyor 20. Once anobject falls through the scanner and lands on the conveyor 36, thesystem notes the conveyor position of the object. The scannerinformation is processed, and the object (if identified) is associatedwith that conveyor location, and its processing location is identified(as discussed in more detail below). As the conveyor advances, thesystem will know when the object is in the line of activation of aselected diverter, and will activate the diverter to push the objectinto the appropriate carriage. The carriage then moves the object to theassigned bin as discussed in more detail below. In various embodiments,the diverters may push an object off through various other ways, such asusing a robot or a diverting guide, and in further embodiments, thediverters may pull an object off of the conveyor.

FIG. 9 shows a processing system 100′ similar to that shown in FIG. 8(where the identical components have the same reference numbers), exceptthat the shuttle sections 74′ of FIG. 8 are positioned alongside(parallel with) the conveyor 36′. In particular, a first diverter 70′may push an object into a carriage 80′ at one end of a shuttle section74′, while a second diverter 70″ may push an object into a carriage 80″in the middle of a shuttle section 74″. In accordance with furtherembodiments, many different arrangements are possible, and each iswithin the spirit and scope of the present invention. Each drawer 82′and 82″ may as discussed below, and the indicator lights 84′, 84″ may belocated above the drawers 82′, 82″.

Similarly, the diverters 70′, 70″ are in communication with thecontroller 78, which is in communication with the scanner 34 as well asthe indexing position of the conveyor 36′. Again, in variousembodiments, the diverters may push an object off through various otherways, such as using a robot or a diverting guide, and in furtherembodiments, the diverters may pull an object off of the conveyor. Oncean object falls through the scanner and lands of the conveyor, thesystem notes the conveyor position of the object. The scannerinformation is processed, and the object (if identified) is associatedwith that conveyor location, and its processing location is identified(as discussed in more detail below). Again, as the conveyor advances,the system will know when the object is in the line of activation of aselected diverter, and will activate the diverter to push the objectinto the appropriate carriage. The carriage then moves the object to theassigned bin as discussed in more detail below.

As further shown with reference to FIG. 10, each shuttle section 74includes a carriage 80 that shuttles back and forth between destinationchutes 84 that include guide walls 85 that lead to two rows of bins 90,92 on either side of track 88. As further shown in FIGS. 11 and 12 (withthe guide walls 85 removed for clarity) the carriage 80 travels alongthe track 88 and carries objects to a desired destination bin 90, 92,and tilts, dropping the object 14 (having indicia 15 such as a bar codethat was detected by the scanner 34) into the desired destination bin.The guide walls serve to guide the object as it falls so that the objectdoes not accidently drop into a neighboring bin. As further shown inFIG. 13, each bin (90, 92), may include one or more pairs of emitters 96and sensors 98 at the top of the bin. Output from a sensor 98 that isrepresentative of a prolonged interruption from the associated source,may be used to determine that the bin is full.

Again, a central computing and control station 78 communicates withother computers distributed in the other components, and alsocommunicates with the customer information system, provides a userinterface, and coordinates all processes. As further shown in FIG. 10,each processing bin 90, 92 of each shuttle section 74 may include a pullout drawer 82 from which each of the two opposing processing bins (e.g.,90, 92) may be accessed and emptied. Each pull-out drawer 82 may alsoinclude light indicators 94 to indicate when the processing bin (e.g.,90, 92) is either full or is ready to be emptied based on systemheuristics, e.g., that the bin is statistically unlikely to receiveanother object soon. In other embodiments, such lights may be positionedabove the respective bin. Each drawer may also include a lock 99 that aperson must unlock to pull out the drawer 82. The lock includes sensorsthat communicate with the controller 78, and when a drawer is unlocked,the system knows not to sort to either bin in the unlocked drawer. Thisway, the system may continue operating while drawers are pulled and binsare emptied.

In accordance with further embodiments of the invention and as shown inFIG. 14, a system of the invention may include a track 102 along whichcarriages 100 may travel in one direction past a plurality of processingbins 104. The remaining items of the system having reference numerals incommon with the system of FIG. 1 are the same as those of the system ofFIG. 1. Each carriage 100 may be dynamically programmed to dump itscontained object 14 into an assigned processing bin 104 based on anassigned sortation scheme. As further shown in FIGS. 15 and 16, thecarriage 100 travels along the track 102 and carries objects to adesired processing bin, and tilts, dropping the object 14 into thedesired destination bin as shown in FIG. 16.

FIG. 14 shows a processing system 200 similar to that of systems 100,100′ (with similar element bears similar reference numerals), exceptthat the system 200 includes carriages 202 that ride along a track(e.g., a circular track). When a carriage 202 is positioned below thedrop scanner 34, an object falls through the scanner and is identifiedas discussed above. The carriage 202 is then moved between rows of bins206, each of which may include, for example a pre-placed bag. Withfurther reference to FIGS. 15 and 16, when the carriage 202 is moved toa desired processing location, the carriage stops (or slows), and dumpsthe object 14 into the bin 206 (as shown in FIG. 16) similar to theaction of carriage 80 discussed above. Again, the object 14 may includeindicia 15 such as a barcode that was detected by the scanner 34.

As further shown in FIG. 17, when a bins 206 is full (e.g., by sensorsas discussed above, or by the system knowing how many items are in thebin, or by having a human simply decide that a bin is full) a human maythen pick up the bin 206. Upon removing the bin 206, a sensor system 208under the bin will indicate that the bin (that specific bin) has beenremoved. The system may continue processing other bins, but will knownot to sort to the removed bin. A new empty bin 210 may then be replacedon the opened location. Because the assignment of bin processinglocations is dynamic and flexible, no further registration is required.As soon as the bin 210 is placed on the sensor 208, the system will knowthat there is a new unassigned bin ready for dynamic processing asdiscussed further below.

In accordance with various embodiments therefore, a system may providethat a portion of the input stream is selectively adjusted by therobotic arm to provide a singulated stream of objects (as may bedetected and confirmed by a perception unit). In particular objects areidentified by the primary perception unit 22 as being selected forremoval (simply to provide a singulated stream of objects), and therobotic arm 24 is engaged to selectively remove objects from the inputstream to create the singulated stream of objects. In furtherembodiments, diverters as discussed above may be used for this purpose.The removed objects are placed by the robotic arm onto a return chute 96that returns the selected objects to the input bin. Such recirculationis for the purpose of providing the singulated stream of objects.Significantly, a singulated stream of objects is provided, and thissingulated stream of objects may be delivered to a perception unit (asdiscussed above) as a singulated stream without requiring that a roboticsystem place objects into the perception unit. If an object is notidentified or is otherwise not able to be processed, it may fall to anexception bin 38 as discussed above, and either returned to arecirculation area or hand processed by a person.

The assignment of processing bins may also be dynamic. For example,systems in accordance with further embodiments, provide improvedtransport and conveyor systems to provide a singulated stream ofobjects, and to provide dynamically changing patterns of objecthandling, with resulting efficiencies in the sortation process, lowerspace requirements, lower demand for manual operations, and as aconsequence, lower capital and operating costs for the entire system.

During use, the sorting station may select an object and then identifythe selected object by the perception system 22 (or may detect anidentity of an object using a scanner on the articulated arm, or may usethe robotic arm to move the object to a detection device). In furtherembodiments, the robotic arm may even hold an object in the perceptionsystem 28 for object identification only. If the object has an assignedbin or a new bin is available, then the end effector will drop theobject through the perception system; otherwise the robotic arm willpull the object from the perception system 28 and place it on the returnchute 96. The system assigns a bin to the object if a new bin isavailable and the object is not yet assigned a bin at that sortingstation. What is significant is that the sorting station is notpre-assigned a large set of collection bins assigned to all possibleobjects that may appear in the input path. Further, the centralcontroller may employ a wide variety of heuristics that may furthershape the process of dynamically assigning objects to collection bins asdiscussed in more detail below. Once bins are either filled or otherwisecompleted, the completed bins are signaled as being done and ready forfurther processing (e.g., by lights 72 associated with bin 90, 92 inFIG. 10).

As shown in FIG. 18, a sortation process of the invention at a sortingstation may begin (step 400) by providing a singulated stream of objectsthat, one at a time, drop an object into the drop scanner (step 402).The system then identifies the new object (step 404). The system thenwill determine whether the object is yet assigned to any collection bin(step 406). If not, the system will determine whether a next bin isavailable (step 408). If no next bin is available (step 410), therobotic system will return the object to the input buffer (step 410) andreturn to step 402. Alternatively, the system can pick one of thecollection bins that is in process and decide that it can be emptied tobe reused for the object in hand, at which point the control system canempty the collection bin or signal a human worker to do it. If a nextbin is available (and the system may permit any number of bins perstation), the system will then assign the object to a next bin (step412). The system then places the object into the assigned bin (step414). The system then returns to step 402 until finished. Again, incertain embodiments, the secondary conveyor may be an indexed conveyorthat moves in increments each time an object is dropped onto theconveyor. The system may then register the identity of the object,access a warehouse manifest, and determine an assigned bin location orassign a new bin location.

A process of the overall control system is shown, for example, in FIG.19. The overall control system may begin (step 500) by permitting a newcollection bin at each station to be assigned to a group of objectsbased on overall system parameters (step 502) as discussed in moredetail below. The system then identifies assigned bins correlated withobjects at each station (step 504), and updates the number of objects ateach bin at each station (step 506). The system then determines thatwhen a bin is either full or the system expects that the associatedsorting station is unlikely to see another object associated with thebin, the associated sorting station robotic system will then place thecompleted bin onto an output conveyor, or signal a human worker to comeand empty the bin (step 508), and then return to step 502.

Systems of various embodiments provide numerous advantages because ofthe inherent dynamic flexibility. The flexible correspondence betweensorter outputs and destinations provides that there may be fewer sorteroutputs than destinations, so the entire system may require less space.The flexible correspondence between sorter outputs and destinations alsoprovides that the system may choose the most efficient order in which tohandle objects, in a way that varies with the particular mix of objectsand downstream demand. The system is also easily scalable, by addingsorters, and more robust since the failure of a single sorter might behandled dynamically without even stopping the system. It should bepossible for sorters to exercise discretion in the order of objects,favoring objects that need to be handled quickly, or favoring objectsfor which the given sorter may have a specialized gripper.

In accordance with certain embodiments, therefore, the system provides asortation system that employs a buffer at the infeed stage enablingscalable and flexible induction of objects into the system. The buffermay include a single conveyor, a circulating conveyor or multipleconveyors, possibly to separate disorganized objects from organizedobjects. In further embodiments, the invention provides a sortationsystem employing a plurality of sorters flexibly connected to bothupstream and downstream processes. The system may also employ a flexibledestination stage, including a process for dynamically changing thecorrespondence of sorter outputs and system destinations using a switchbased on heuristics from the sortation process. The system maydynamically map sorter outputs to system destinations based on long-termhistorical usage trends and statistics, or items already processed, orcurrent contents of other dynamically allocated sorter outputs, oraverage, minimum or maximum time-to-sort associated with each sorteroutput, or physical characteristics of the items sorted, or a prioriinformation, or known future deliveries, or location within a facility,including the physical location relative to other allocated sorteroutputs (e.g., above, beside, on or nearby), or incoming shipments, aswell as knowing what items are currently upstream of the sortationprocess and combinations of the above. Further, systems of embodimentsof the invention provide that information regarding correspondencebetween sorter outputs to system destinations may be provided to anautomated system for sorting.

By making use of heuristics, the mapping of sorter outputs to systemdestinations can be improved substantially over traditional fixedallocation. Destinations may be assigned on the fly, reducing wastedspace from unused sorter outputs and decreasing the time it takes toprocess incoming objects. Long-term historic trends may be used toallocate sorter outputs when the next incoming group of objects iseither in-part or entirely unknown. Historical usage patterns provideinsight into when objects bound for certain destinations can be expectedto arrive, the number of objects bound for each destination expected forany given time, and the probable physical properties of these incomingobjects.

The system provides in a specific embodiment an input system thatinterfaces to the customer's conveyors and containers, stores parcelsfor feeding into the system, and feeds those parcels into the system ata moderate and controllable rate. In one embodiment, the interface tothe customer's process takes the form of a Gaylord dumper, but manyother embodiments are possible. In one embodiment, feeding into thesystem is achieved by an inclined cleated conveyor with overheadbaffles. A key to the efficient operation of the system is to feedparcels in at a modest controlled rate. Many options are available,including variations in the conveyor slope and speed, the presence, sizeand structure of cleats and baffles, and the use of sensors to monitorand control the feed rate.

The system includes in a specific embodiment a primary perception systemthat monitors the stream of parcels on the primary conveyor. Wherepossible the primary perception system may identify the parcel to speedor simplify subsequent operations. For example, knowledge of the parcelson the primary conveyor may enable the system to make better choices onwhether to pick up a parcel rather than let it pass to the exceptionbin, which parcels to pick up first, or on how to allocate output bins.The main job of the primary perception system is to assist in providinga singulated stream of objects.

As also discussed above, the system includes in a specific embodiment adrop scanner that scans objects dropped through it, reads bar codes,confirms that an object is correctly singulated, and obtains the desiredprocessing bin. Other embodiments are possible, including use of aconventional scan tunnel, or relying entirely on primary perception toidentify objects. Another embodiment would include a recirculatingprimary conveyor, in which objects not identified on the first passmight be recirculated, perhaps by falling back into the infeed.

The systems therefore, include in certain embodiments a primarytransport system that transports singulated and identified parcelstowards the output. In one embodiment the primary transport is aconveyor belt with dividers to preserve singulation. The conveyor beltis indexed one position at a time, positioning parcels for transfer to asecondary transport system. Parcels are transferred by a diverter whichpushes them across the conveyor to the secondary transport. When asingulation or identification failure occurs, the parcel remains onsecondary transport and falls into the secondary exception bin. Otherembodiments are possible, for example a cross-belt system, a slidingshoe diverter system, or a tilt-tray system.

The system also includes in a specific embodiment a secondary transportsystem which carries parcels to the processing bins. In one embodimentthe secondary transport is a reciprocating shuttle which travelslinearly along the tops of two rows of bins, then tilts to one side orthe other to drop the parcel into the desired bin, and then returns to ahome position ready to receive another parcel. Other embodiments arepossible, for example a tilt-tray system, a cross-belt system, or a shoediverter system.

The system includes means to interface to the customer's outgoing parcelconveyance systems. In a specific embodiment the bins are lined withbags. When the bin is full as determined by sensors or by monitoringsystem operation, a human operator pulls the bin out of place, removesthe bag, labels the bag, and places the bag on an appropriate conveyor.Other embodiments are possible, including automatic bagging systems,bins without bags, bins that are automatically ejected from the systemand replace with new bins. In one embodiment the system continuesoperation during the bagging operation by avoiding induction of parcelsdestined for that particular bin, or by allocating a different bin forthe same destination.

In accordance with a specific embodiment, the invention provides a userinterface that conveys all relevant information to operators,management, and maintenance personnel. In a specific embodiment this mayinclude lights indicating bins that should be bagged, lights indicatingbins not completely returned to position, lights indicating operationalstatus, displays for monitoring the operation of the primary perceptionsystem and the drop scanner, displays monitoring grasping and robotmotion, monitoring of exception bin levels and input hopper level, andoperating mode of the entire system. Additional information includedmight be rate of parcel processing and additional statistics such asexception and error rates. In a specific embodiment the systemautomatically prints bag labels and scans bag labels before the operatorplaces them on the output conveyor.

In accordance with a further embodiment, a system of the inventionincorporates software systems that interface with the customer'sdatabases and other information systems, to provide operationalinformation to the customer's system and to query the customer's systemfor parcel information.

The invention has many variations possible to suit the varyingcharacteristics of the task. The number of bins serviced by a shuttlemay be greater or lesser. The number of shuttles may be increased. Insome embodiments there may be more than one secondary transport system,serving additional sets of shuttles. In other embodiments there may bemore than one robot.

Some applications may not justify the use of a robot, and one embodimentwould then use a human to perform induction. In another embodiment, thesystem might include a conventional unit sortation conveyor such as atilt-tray or cross belt sorter, with the robot performing induction.

In accordance with various embodiments, therefore, the inventionprovides a robotic system for sorting parcels to desired outputdestination bins. The system includes an input system for acceptingparcels from the customer and feeding them into the system; asingulation system to transform the stream of parcels into a sequence ofdiscrete parcels; an identification system to read identifying marks orotherwise determine the desired destination; and an output system forconveying each parcel to a desired processing bin, from which it can beconveyed to the customer's desired destination.

In further embodiments, the infeed system includes an inclined conveyorwith cleats, the infeed system includes an inclined conveyor withbaffles, and/or the infeed system includes a sensor to monitor parcelstream height, breadth or rate, so that the conveyor rate may bemodulated to control parcel rate. In accordance with furtherembodiments, the singulation system includes a primary perception systemto monitor parcels.

In accordance with certain embodiments, the primary perception systemmay determine parcel identity, may determine grasp locations, and/or maydetermine parcel class. In accordance with further embodiments, thesingulation system may include one or more robotic manipulators withgrippers, and one or more of the grippers is a vacuum gripper, thevacuum gripper may be equipped with a pressure sensor, and/or one ormore of the grippers may be equipped with a force sensor. In accordancewith further embodiments, the singulation system may include one or morerobotic manipulators with end effectors suited to pushing, and theidentification system may include one or more parcel scanners toidentify parcels, e.g., a drop scanner.

In accordance with certain embodiments, the output system includes oneor more conveyors which combine to transfer parcels to bins, theconveyors are organized as one or more primary conveyors; with eachprimary conveyor transferring parcels to one or more secondaryconveyors, and/or one or more primary conveyors is a cleated conveyorcapable of indexing one position at a time. In accordance with furtherembodiments, diverters transfer parcels from the primary conveyors tosecondary conveyors, the diverters are linear actuators attached tosweeper diverters, one or more of the conveyors is a reciprocatingshuttle, and/or the reciprocating shuttle includes a tilt axis to dropparcels.

In accordance with further embodiments, the invention provides a methodfor automatically sorting parcels and conveying parcels to desiredoutput destinations. The method includes the steps of feeding thecustomer parcels into the system infeed, conveying the parcels from thesystem infeed to a singulation system, singulating the parcels andmoving them to an identification system, identifying the parcels andtheir associated desired destinations, and conveying each parcel to adesired destination.

In accordance with further embodiments, the infeed conveyor's design andcontrol are optimized to present the parcels in a stream best suited tosubsequent perception and handling, grasp points are determinedautomatically, grasp points are determined from computer visionalgorithms, and/or singulation is accomplished by grasping singleparcels and moving them individually to subsequent processing. Inaccordance with further embodiments, sensor information is used toestimate grasp state including contact with parcel, quality of vacuumseal, parcel weight, parcel mass distribution, and parcel positionrelative to gripper, and/or grasp state estimates are used to determinewhether the grasp is adequate, and to modulate the subsequent motion toavoid drops. In accordance with further embodiments, the robot arm'smotion is determined by motion planning software cognizant of initialand final waypoints, surrounding obstacles, and constraints necessary tomaintain a secure grasp and/or the correspondence of output bins tocustomer destinations are determined dynamically to optimize systemthroughput.

Those skilled in the art will appreciate that numerous modifications andvariations may be made to the above disclosed embodiments withoutdeparting from the spirit and scope of the present invention.

What is claimed is:
 1. A method of providing singulation of objects,comprising: moving objects to be sorted from an infeed hopper along anupward direction on an input conveyor to a primary conveyor; detectingthe objects moving on the primary conveyor; selecting certain objectsfor removal from the primary conveyor to provide a singulated stream ofobjects on the primary conveyor; and removing the certain selectedobjects from the primary conveyor to the infeed hopper.
 2. The method asclaimed in claim 1, wherein the input conveyor is a cleated conveyor. 3.The method as claimed in claim 1, wherein the primary conveyor is acleated conveyor.
 4. The method as claimed in claim 1, wherein theprimary conveyor is an adjustable speed conveyor.
 5. The method asclaimed in claim 1, wherein the primary conveyor moves in increments. 6.The method as claimed in claim 1, wherein the singulated stream ofobjects includes heterogeneous objects.
 7. The method as claimed inclaim 1, wherein removing the certain selected objects from the primaryconveyor to the infeed hopper comprises moving the certain selectedobjects from the primary conveyor to a chute that leads in a downwarddirection back toward the infeed hopper.
 8. The method as claimed inclaim 7, wherein moving the certain selected objects from the primaryconveyor to the chute that leads back toward the infeed hopper comprisespulling the certain selected objects, without lifting the certainselected objects, from the primary conveyor onto the chute using adiverter having an actuatable pull element.
 9. The method as claimed inclaim 7, wherein moving the certain selected objects from the primaryconveyor to the chute that leads back toward the infeed hopper comprisespushing the certain selected objects from the primary conveyor onto thechute using a diverter having an actuatable push element.
 10. The methodas claimed in claim 7, wherein moving the certain selected objects fromthe primary conveyor to the chute that leads back toward the infeedhopper comprises lifting the certain selected objects from the primaryconveyor and placing the certain selected objects onto the chute usingan end effector of a robotic arm.
 11. The method as claimed in claim 1,further comprising: dropping the singulated stream of objects, oneobject at a time, from the primary conveyor through an opening definedin a drop perception system, the drop perception system including aplurality of perception units; and detecting identifying indicia locatedon a surface on an object using the plurality of perception units as theobject falls through the opening of the drop perception system.
 12. Themethod as claimed in claim 11, wherein dropping the singulated stream ofobjects comprises dropping the singulated stream of objects, one objectat a time, through the opening of the drop perception system onto asecondary conveyor, the method further comprising: urging an object offthe secondary conveyor into a carriage that moves reciprocally along atrack between two rows of destination bins; moving the carriage in afirst direction along the track to a position adjacent to a destinationbin selected based on the identifying indicia of the object; tilting thecarriage towards one side of the track to drop the object into theselected destination bin in one of the two rows of destination bins; andmoving the carriage in an reverse direction along the track to return toa load position adjacent to the secondary conveyor.
 13. The method asclaimed in claim 11, wherein dropping the singulated stream of objectscomprises dropping the singulated stream of objects, one object at atime, through the opening of the drop perception system into a carriagethat moves reciprocally along a track between two rows of destinationbins, the method further comprising: moving the carriage in a firstdirection along the track to a position adjacent to a destination binselected based on the identifying indicia of the object; tilting thecarriage towards one side of the track to drop the object into theselected destination bin in one of the two rows of destination bins; andmoving the carriage in an reverse direction along the track to return toa load position below the drop perception system.
 14. A method ofproviding singulation of objects, comprising: moving objects to besorted from a source area along a first direction on a primary conveyor;detecting objects on the primary conveyor; selecting certain selectedobjects for removal from the primary conveyor; removing the certainselected objects from the primary conveyor to generate a singulatedstream of objects; dropping the singulated stream of objects, one objectat a time, from the primary conveyor onto a secondary conveyor; urgingan object off the secondary conveyor into a carriage that movesreciprocally along a track between two rows of destination bins; movingthe carriage in a first direction along the track to a position adjacentto a selected destination bin; tilting the carriage towards one side ofthe track to drop the object into the selected destination bin in one ofthe two rows of destination bins; and moving the carriage in an reversedirection along the track to return to a load position adjacent to thesecondary conveyor.
 15. The method as claimed in claim 14, wherein thesource area includes a contained area from which objects are drawn by aninput conveyor.
 16. The method as claimed in claim 15, wherein removingthe certain selected objects includes returning the certain selectedobjects to the source area.
 17. The method as claimed in claim 16,wherein the certain selected objects are returned to the source area byuse of a chute.
 18. The method as claimed in claim 14, wherein the inputconveyor is a cleated conveyor.
 19. The method as claimed in claim 14,wherein the primary conveyor is a cleated conveyor.
 20. The method asclaimed in claim 14, wherein the primary conveyor moves in increments.21. The method as claimed in claim 14, wherein the singulated stream ofobjects is a singulated stream of heterogeneous objects.
 22. The methodas claimed in claim 14, wherein removing the certain selected objectsfrom the conveying system comprises sliding the certain selected objectsfrom the primary conveyor.
 23. The method as claimed in claim 22,wherein sliding the certain selected objects comprises sliding thecertain selected objects without lifting the certain selected objectsfrom the primary conveyor.
 24. The method as claimed in claim 22,wherein sliding the certain selected objects comprises pushing thecertain selected objects from the primary conveyor.
 25. The method asclaimed in claim 22, wherein sliding the certain selected objectscomprises pulling the certain selected objects from the primaryconveyor.
 26. A method of providing singulation of objects, comprising:moving objects to be sorted from a source area along a first directionon a primary conveyor; detecting the objects on the primary conveyor;selecting certain selected objects for removal from the primaryconveyor; removing the certain selected objects from the primaryconveyor to provide a singulated stream of objects by returning thecertain selected objects to the source area; dropping the singulatedstream of objects, one object at a time, from the primary conveyor intoa carriage that moves reciprocally along a track between two rows ofdestination bins; moving the carriage in a first direction along thetrack to a position adjacent to a selected destination bin; tilting thecarriage towards one side of the track to drop the object into theselected destination bin in one of the two rows of destination bins; andmoving the carriage in an reverse direction along the track to return toa load position below the primary conveyor.
 27. The method as claimed inclaim 26, wherein the source area includes a contained area from whichobjects are drawn by an input conveyor.
 28. The method as claimed inclaim 27, wherein the input conveyor is a cleated conveyor.
 29. Themethod as claimed in claim 26, wherein the step of moving objectsinvolves the use of a cleated conveyor.
 30. The method as claimed inclaim 26, wherein the primary conveyor moves in increments.
 31. Themethod as claimed in claim 26, wherein the singulated stream of objectsis a singulated stream of heterogeneous objects.
 32. The method asclaimed in claim 26, wherein removing the certain selected objects fromthe conveying system includes sliding the certain selected objects fromthe primary conveyor.
 33. The method as claimed in claim 32, whereinsliding the certain selected objects includes sliding the certainselected objects without lifting the certain selected objects from theprimary conveyor.
 34. The method as claimed in claim 32, wherein slidingthe certain selected objects includes pushing the certain selectedobjects from the conveying system.
 35. The method as claimed in claim32, wherein sliding the certain selected objects includes pulling thecertain selected objects from the conveying system.